[Honestly, it's telling of their friendship that Bakugou even came out here to help him at all, much less this late into the night. Kirishima hadn't intended for it to take this long, but...he's really bad at math. Like, really bad. He hears that growling long before it becomes a problem, but he tries to work through it even though he has the sneaking suspiscion that his most recent try at this problem is still wrong.

The fist coming down on his head comes at little surprise, but as Bakugou expected he takes it in stride. If anything it just wounds his dignity more than his head, startling him into pressing down too hard and snapping the lead in his pencil.

He turns to look over his shoulder at Bakugou, flustered.]

You know how I am with this kinda stuff, dude! Every time I work it out I get a different answer!

[He scrubs a hand through his hair, digging at it in frustration with his fingers for a moment as he stares down at the crushed lead on his paper along with the smears of much erasing and redoing.]

If you wanna go ahead to bed you can, but I'm stayin' up. I just gotta get this stuff down before the test tomorrow or I'm sunk.